Java 将ArrayAdapter设置为ListView时出现NullPointerException 正道 创建视图上的公共视图（布局、充气机、视图组容器、捆绑包保存实例状态）{ 视图根=充气机。充气（R.layout.fragment_蔬菜，容器，假）； li

将ArrayAdapter设置为ListView时出现NullPointerException 正道 创建视图上的公共视图（布局、充气机、视图组容器、捆绑包保存实例状态）{ 视图根=充气机。充气（R.layout.fragment_蔬菜，容器，假）； listView=（listView）root.findViewById（R.id.sellects\u list\u view）； setAdapter（新的ArrayAdapter（getActivity（），android.R.layout.simple_list_item_1，days））； 返回根；

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我爱你。非常感谢。如果你能告诉问题的话，这将是非常有帮助的。

package com.thefuelcompany.rocketmandi;

import android.app.Activity;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;



/**
 * Created by pradumanpraduman on 11/03/16.
 */

/**
I am trying to create a list of vegetables and show it in a list view. 
The inflator was working fine but getting a null pointer exception while 
setting adapter for the list view.
*/
public class FragmentVegetables extends Fragment {
    ListView l;
    String [] days = {"Monday","Tuesday","Wed","Thu"};
    public View onCreateView(LayoutInflater inflater, ViewGroup container , Bundle saveInstanceState){
        l = (ListView) container.findViewById(R.id.vegetables_list_view);
        l.setAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1,days));
    return inflater.inflate(R.layout.fragment_vegetables, container, false);

    }
}


/**
There is a log of error.
*/



 enabling -Xcheck:jni
    03-14 12:34:30.430 1543-1556/? I/art: Debugger is no longer active
    03-14 12:34:30.582 1543-1572/? D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
    03-14 12:34:30.594 1543-1543/? D/Atlas: Validating map...
    03-14 12:34:30.629 1543-1543/? W/FragmentManager: moveToState: Fragment state for FragmentFruits{3e79e066 #0 id=0x7f0c0054} not updated inline; expected state 3 found 2
    03-14 12:34:30.630 1543-1543/? D/AndroidRuntime: Shutting down VM
    03-14 12:34:30.632 1543-1543/? E/AndroidRuntime: FATAL EXCEPTION: main
                                                     Process: com.thefuelcompany.rocketmandi, PID: 1543

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
                                                     at com.thefuelcompany.rocketmandi.FragmentVegetables.onCreateView(FragmentVegetables.java:22)
                                                     at android.support.v4.app.Fragment.performCreateView(Fragment.java:1974)
                                                     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
                                                     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252)
                                                     at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
                                                     at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
                                                     at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
                                                     at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:164)
                                                     at android.support.v4.view.ViewPager.populate(ViewPager.java:1177)
                                                     at android.support.v4.view.ViewPager.populate(ViewPager.java:1025)
                                                     at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1545)
                                                     at android.view.View.measure(View.java:17565)
                                                     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5537)
                                                     at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
                                                     at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
                                                     at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
                                                     at android.view.View.measure(View.java:17565)
                                                     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5537)
                                                     at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
                                                     at android.view.View.measure(View.java:17565)
                                                     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5537)
                                                     at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
                                                     at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
                                                     at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
                                                     at android.view.View.measure(View.java:17565)
                                                     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5537)
                                                     at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
                                                     at com.android.internal

    .policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2615)
                                                             at android.view.View.measure(View.java:17565)
                                                             at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2045)
                                                             at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1196)
                                                             at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1409)
                                                             at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1084)
                                                             at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5990)
                                                             at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
                                                             at android.view.Choreographer.doCallbacks(Choreographer.java:580)
                                                             at android.view.Choreographer.doFrame(Choreographer.java:550)
                                                             at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
                                                             at android.os.Handler.handleCallback(Handler.java:739)
                                                             at android.os.Handler.dispatchMessage(Handler.java:95)
                                                             at android.os.Looper.loop(Looper.java:135)
                                                             at android.app.ActivityThread.main(ActivityThread.java:5343)
                                                             at java.lang.reflect.Method.invoke(Native Method)
                                                             at java.lang.reflect.Method.invoke(Method.java:372)
                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
                                                         at 

    com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
        03-14 12:34:32.663 1543-1543/com.thefuelcompany.rocketmandi I/Process: Sending signal. PID: 1543 SIG: 9

 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle saveInstanceState) {
    View root = inflater.inflate(R.layout.fragment_vegetables, container, false);
    listView = (ListView) root.findViewById(R.id.vegetables_list_view);
    listView.setAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1,days));
    return root;